Merge pull request #8827 from m-kuhn/gpkg_transaction_test

sqlite_fetch_and_increment cached mode for transactions
qgis · Jan 11, 2019 · 2664737 · 2664737
2 parents b49e940 + 5962afd
commit 2664737
Show file tree

Hide file tree

Showing 6 changed files with 4,055 additions and 56 deletions.
diff --git a/resources/function_help/json/sqlite_fetch_and_increment b/resources/function_help/json/sqlite_fetch_and_increment
@@ -1,16 +1,17 @@
 {
   "name": "sqlite_fetch_and_increment",
   "type": "function",
-  "description": "Manage autoincrementing values in sqlite databases.<p>SQlite default values can only be applied on insert and not prefetched.</p><p>This makes it impossible to acquire an incremented primary key via AUTO_INCREMENT before creating the row in the database. Sidenote: with postgres, this works via the option <i>evaluate default values</i>.</p><p>When adding new features with relations, it is really nice to be able to already add children for a parent, while the parents form is still open and hence the parent feature uncommitted.</p><p>To get around this limitation, this function can be used to manage sequence values in a separate table on sqlite based formats like gpkg.</p><p>The sequence table will be filtered for a sequence id (filter_attribute and filter_value) and the current value of the id_field will be incremented by 1 ond the incremented value returned.</p><p>If additional columns require values to be specified, the default_value map can be used for this purpose.</p><p><b>Note</b><br/>This function modifies the target sqlite table. It is intended for usage with default value configurations for attributes.</p>",
+  "description": "Manage autoincrementing values in sqlite databases.<p>SQlite default values can only be applied on insert and not prefetched.</p><p>This makes it impossible to acquire an incremented primary key via AUTO_INCREMENT before creating the row in the database. Sidenote: with postgres, this works via the option <i>evaluate default values</i>.</p><p>When adding new features with relations, it is really nice to be able to already add children for a parent, while the parents form is still open and hence the parent feature uncommitted.</p><p>To get around this limitation, this function can be used to manage sequence values in a separate table on sqlite based formats like gpkg.</p><p>The sequence table will be filtered for a sequence id (filter_attribute and filter_value) and the current value of the id_field will be incremented by 1 ond the incremented value returned.</p><p>If additional columns require values to be specified, the default_value map can be used for this purpose.</p><p><b>Note</b><br/>This function modifies the target sqlite table. It is intended for usage with default value configurations for attributes.</p><p>When the database parameter is a layer and the layer is in transaction mode, the value will only be retrieved once during the lifetime of a transaction and cached and incremented. This makes it unsafe to work on the same database from several processes in parallel.</p>",
   "arguments": [
-	  {"arg":"database", "description":"Path to the sqlite file"},
+	  {"arg":"database", "description":"Path to the sqlite file or geopackage layer"},
     {"arg":"table", "description":"Name of the table that manages the sequences"},
     {"arg":"id_field", "description":"Name of the field that contains the current value"},
     {"arg":"filter_attribute", "description":"Name the field that contains a unique identifier for this sequence. Must have a UNIQUE index."},
     {"arg":"filter_value", "description":"Name of the sequence to use."},
     {"arg":"default_values", "description":"Map with default values for additional columns on the table. The values need to be fully quoted. Functions are allowed.", "optional": true}
   ],
   "examples": [
+    { "expression":"sqlite_fetch_and_increment(@layer, 'sequence_table', 'last_unique_id', 'sequence_id', 'global', map('last_change','date(''now'')','user','''' || @user_account_name || ''''))", "returns":"0"},
     { "expression":"sqlite_fetch_and_increment(layer_property(@layer, 'path'), 'sequence_table', 'last_unique_id', 'sequence_id', 'global', map('last_change','date(''now'')','user','''' || @user_account_name || ''''))", "returns":"0"}
   ]
 }
diff --git a/src/core/expression/qgsexpressionfunction.cpp b/src/core/expression/qgsexpressionfunction.cpp
@@ -48,6 +48,8 @@
 #include "qgsvectorlayerfeatureiterator.h"
 #include "qgsproviderregistry.h"
 #include "sqlite3.h"
+#include "qgstransaction.h"
+#include "qgsthreadingutils.h"
 
 const QString QgsExpressionFunction::helpText() const
 {
@@ -1375,78 +1377,163 @@ static QVariant fcnNumSelected( const QVariantList &values, const QgsExpressionC
 
 static QVariant fcnSqliteFetchAndIncrement( const QVariantList &values, const QgsExpressionContext *, QgsExpression *parent, const QgsExpressionNodeFunction * )
 {
-  const QString database = values.at( 0 ).toString();
-  const QString table = values.at( 1 ).toString();
-  const QString idColumn = values.at( 2 ).toString();
-  const QString filterAttribute = values.at( 3 ).toString();
-  const QVariant filterValue = values.at( 4 ).toString();
-  const QVariantMap defaultValues = values.at( 5 ).toMap();
+  static QMap<QString, qlonglong> counterCache;
+  QVariant functionResult;
 
+  std::function<void()> fetchAndIncrementFunc = [ =, &functionResult ]()
+  {
+    QString database;
+    const QgsVectorLayer *layer = QgsExpressionUtils::getVectorLayer( values.at( 0 ), parent );
 
-  // read from database
-  sqlite3_database_unique_ptr sqliteDb;
-  sqlite3_statement_unique_ptr sqliteStatement;
+    if ( layer )
+    {
+      const QVariantMap decodedUri = QgsProviderRegistry::instance()->decodeUri( layer->providerType(), layer->dataProvider()->dataSourceUri() );
+      database = decodedUri.value( QStringLiteral( "path" ) ).toString();
+      if ( database.isEmpty() )
+      {
+        parent->setEvalErrorString( QObject::tr( "Could not extract file path from layer `%1`." ).arg( layer->name() ) );
+      }
+    }
+    else
+    {
+      database = values.at( 0 ).toString();
+    }
 
-  if ( sqliteDb.open_v2( database, SQLITE_OPEN_READWRITE, nullptr ) != SQLITE_OK )
-  {
-    parent->setEvalErrorString( QObject::tr( "Could not open sqlite database %1. Error %2. " ).arg( database, sqliteDb.errorMessage() ) );
-    return QVariant();
-  }
+    const QString table = values.at( 1 ).toString();
+    const QString idColumn = values.at( 2 ).toString();
+    const QString filterAttribute = values.at( 3 ).toString();
+    const QVariant filterValue = values.at( 4 ).toString();
+    const QVariantMap defaultValues = values.at( 5 ).toMap();
 
-  QString currentValSql;
-  currentValSql = QStringLiteral( "SELECT %1 FROM %2" ).arg( QgsSqliteUtils::quotedIdentifier( idColumn ), QgsSqliteUtils::quotedIdentifier( table ) );
-  if ( !filterAttribute.isNull() )
-  {
-    currentValSql += QStringLiteral( " WHERE %1 = %2" ).arg( QgsSqliteUtils::quotedIdentifier( filterAttribute ), QgsSqliteUtils::quotedValue( filterValue ) );
-  }
+    // read from database
+    sqlite3_database_unique_ptr sqliteDb;
+    sqlite3_statement_unique_ptr sqliteStatement;
 
-  int result;
-  sqliteStatement = sqliteDb.prepare( currentValSql, result );
-  if ( result == SQLITE_OK )
-  {
-    qlonglong nextId = 0;
-    if ( sqliteStatement.step() == SQLITE_ROW )
+    if ( sqliteDb.open_v2( database, SQLITE_OPEN_READWRITE, nullptr ) != SQLITE_OK )
     {
-      nextId = sqliteStatement.columnAsInt64( 0 ) + 1;
+      parent->setEvalErrorString( QObject::tr( "Could not open sqlite database %1. Error %2. " ).arg( database, sqliteDb.errorMessage() ) );
+      functionResult = QVariant();
+      return;
     }
 
-    QString upsertSql;
-    upsertSql = QStringLiteral( "INSERT OR REPLACE INTO %1" ).arg( QgsSqliteUtils::quotedIdentifier( table ) );
-    QStringList cols;
-    QStringList vals;
-    cols << QgsSqliteUtils::quotedIdentifier( idColumn );
-    vals << QgsSqliteUtils::quotedValue( nextId );
+    QString errorMessage;
+    QString currentValSql;
+
+    qlonglong nextId;
+    bool cachedMode = false;
+    bool valueRetrieved = false;
+
+    QString cacheString = QStringLiteral( "%1:%2:%3:%4:%5" ).arg( database, table, idColumn, filterAttribute, filterValue.toString() );
 
-    if ( !filterAttribute.isNull() )
+    // Running in transaction mode, check for cached value first
+    if ( layer && layer->dataProvider() && layer->dataProvider()->transaction() )
     {
-      cols << QgsSqliteUtils::quotedIdentifier( filterAttribute );
-      vals << QgsSqliteUtils::quotedValue( filterValue );
+      cachedMode = true;
+
+      auto cachedCounter = counterCache.find( cacheString );
+
+      if ( cachedCounter != counterCache.end() )
+      {
+        qlonglong &cachedValue = cachedCounter.value();
+        nextId = cachedValue;
+        nextId += 1;
+        cachedValue = nextId;
+        valueRetrieved = true;
+      }
     }
 
-    for ( QVariantMap::const_iterator iter = defaultValues.constBegin(); iter != defaultValues.constEnd(); ++iter )
+    // Either not in cached mode or no cached value found, obtain from DB
+    if ( !cachedMode || !valueRetrieved )
     {
-      cols << QgsSqliteUtils::quotedIdentifier( iter.key() );
-      vals << iter.value().toString();
-    }
+      int result = SQLITE_ERROR;
 
-    upsertSql += QLatin1String( " (" ) + cols.join( ',' ) + ')';
-    upsertSql += QLatin1String( " VALUES " );
-    upsertSql += '(' + vals.join( ',' ) + ')';
+      currentValSql = QStringLiteral( "SELECT %1 FROM %2" ).arg( QgsSqliteUtils::quotedIdentifier( idColumn ), QgsSqliteUtils::quotedIdentifier( table ) );
+      if ( !filterAttribute.isNull() )
+      {
+        currentValSql += QStringLiteral( " WHERE %1 = %2" ).arg( QgsSqliteUtils::quotedIdentifier( filterAttribute ), QgsSqliteUtils::quotedValue( filterValue ) );
+      }
 
-    QString errorMessage;
-    result = sqliteDb.exec( upsertSql, errorMessage );
-    if ( result == SQLITE_OK )
-    {
-      return nextId;
+      sqliteStatement = sqliteDb.prepare( currentValSql, result );
+
+      if ( result == SQLITE_OK )
+      {
+        nextId = 0;
+        if ( sqliteStatement.step() == SQLITE_ROW )
+        {
+          nextId = sqliteStatement.columnAsInt64( 0 ) + 1;
+        }
+
+        // If in cached mode: add value to cache and connect to transaction
+        if ( cachedMode && result == SQLITE_OK )
+        {
+          counterCache.insert( cacheString, nextId );
+
+          QObject::connect( layer->dataProvider()->transaction(), &QgsTransaction::destroyed, [cacheString]()
+          {
+            counterCache.remove( cacheString );
+          } );
+        }
+        valueRetrieved = true;
+      }
     }
-    else
+
+    if ( valueRetrieved )
     {
-      parent->setEvalErrorString( QStringLiteral( "Could not increment value: SQLite error: \"%1\" (%2)." ).arg( errorMessage, QString::number( result ) ) );
-      return QVariant();
+      QString upsertSql;
+      upsertSql = QStringLiteral( "INSERT OR REPLACE INTO %1" ).arg( QgsSqliteUtils::quotedIdentifier( table ) );
+      QStringList cols;
+      QStringList vals;
+      cols << QgsSqliteUtils::quotedIdentifier( idColumn );
+      vals << QgsSqliteUtils::quotedValue( nextId );
+
+      if ( !filterAttribute.isNull() )
+      {
+        cols << QgsSqliteUtils::quotedIdentifier( filterAttribute );
+        vals << QgsSqliteUtils::quotedValue( filterValue );
+      }
+
+      for ( QVariantMap::const_iterator iter = defaultValues.constBegin(); iter != defaultValues.constEnd(); ++iter )
+      {
+        cols << QgsSqliteUtils::quotedIdentifier( iter.key() );
+        vals << iter.value().toString();
+      }
+
+      upsertSql += QLatin1String( " (" ) + cols.join( ',' ) + ')';
+      upsertSql += QLatin1String( " VALUES " );
+      upsertSql += '(' + vals.join( ',' ) + ')';
+
+      int result = SQLITE_ERROR;
+      if ( layer && layer->dataProvider() && layer->dataProvider()->transaction() )
+      {
+        QgsTransaction *transaction = layer->dataProvider()->transaction();
+        if ( transaction->executeSql( upsertSql, errorMessage ) )
+        {
+          result = SQLITE_OK;
+        }
+      }
+      else
+      {
+        result = sqliteDb.exec( upsertSql, errorMessage );
+      }
+      if ( result == SQLITE_OK )
+      {
+        functionResult = QVariant( nextId );
+        return;
+      }
+      else
+      {
+        parent->setEvalErrorString( QStringLiteral( "Could not increment value: SQLite error: \"%1\" (%2)." ).arg( errorMessage, QString::number( result ) ) );
+        functionResult = QVariant();
+        return;
+      }
     }
-  }
 
-  return QVariant(); // really?
+    functionResult = QVariant();
+  };
+
+  QgsThreadingUtils::runOnMainThread( fetchAndIncrementFunc );
+
+  return functionResult;
 }
 
 static QVariant fcnConcat( const QVariantList &values, const QgsExpressionContext *, QgsExpression *parent, const QgsExpressionNodeFunction * )

diff --git a/tests/src/core/testqgsexpression.cpp b/tests/src/core/testqgsexpression.cpp
@@ -33,6 +33,7 @@
 #include "qgsrasterlayer.h"
 #include "qgsproject.h"
 #include "qgsexpressionnodeimpl.h"
+#include "qgsvectorlayerutils.h"
 
 static void _parseAndEvalExpr( int arg )
 {
@@ -3298,6 +3299,63 @@ class TestQgsExpression: public QObject
       e = QgsExpression( QStringLiteral( "map('a',1,'bbb',2,'c',3)['b'||'b'||'b']" ) );
       QCOMPARE( e.evaluate( &context ).toInt(), 2 );
     }
+
+
+    void testSqliteFetchAndIncrementWithTranscationMode()
+    {
+      QString testDataDir = QStringLiteral( TEST_DATA_DIR ) + '/';
+      QTemporaryDir tempDir;
+      QFile::copy( testDataDir + QStringLiteral( "kbs.qgs" ), tempDir.filePath( "kbs.qgs" ) );
+      QFile::copy( testDataDir + QStringLiteral( "kbs.gpkg" ), tempDir.filePath( "kbs.gpkg" ) );
+
+      QgsProject *project = QgsProject::instance();
+      QVERIFY( project->read( tempDir.filePath( "kbs.qgs" ) ) );
+
+      QgsVectorLayer *zustaendigkeitskataster = project->mapLayer<QgsVectorLayer *>( QStringLiteral( "zustaendigkeitkataster_2b5bb693_3151_4c82_967f_b49d4d348a17" ) );
+
+      // There is a default expression setup, dear reader of this test
+      QVERIFY( zustaendigkeitskataster->defaultValueDefinition( 0 ).expression().contains( "sqlite_fetch_and_increment" ) );
+
+      zustaendigkeitskataster->startEditing();
+
+      QgsExpressionContext context( QgsExpressionContextUtils::globalProjectLayerScopes( zustaendigkeitskataster ) );
+      QgsFeature feature = QgsVectorLayerUtils::createFeature( zustaendigkeitskataster, QgsGeometry(), QgsAttributeMap(), &context );
+      QCOMPARE( feature.attribute( "T_Id" ).toInt(), 0 );
+      feature.setAttribute( "url_behoerde", "url_behoerde" );
+      feature.setAttribute( "url_kataster", "url_kataster" );
+      zustaendigkeitskataster->addFeature( feature );
+
+      QgsFeature feature2 = QgsVectorLayerUtils::createFeature( zustaendigkeitskataster, QgsGeometry(), QgsAttributeMap(), &context );
+      QCOMPARE( feature2.attribute( "T_Id" ).toInt(), 1 );
+      feature2.setAttribute( "url_behoerde", "url_behoerde_x" );
+      feature2.setAttribute( "url_kataster", "url_kataster_x" );
+      zustaendigkeitskataster->addFeature( feature2 );
+
+      zustaendigkeitskataster->commitChanges();
+      QCOMPARE( zustaendigkeitskataster->dataProvider()->featureCount(), 2l );
+
+      QCOMPARE( zustaendigkeitskataster->editBuffer(), nullptr );
+      QCOMPARE( zustaendigkeitskataster->dataProvider()->transaction(), nullptr );
+
+      zustaendigkeitskataster->startEditing();
+      QgsExpressionContext context2( QgsExpressionContextUtils::globalProjectLayerScopes( zustaendigkeitskataster ) );
+      QgsFeature feature3 = QgsVectorLayerUtils::createFeature( zustaendigkeitskataster, QgsGeometry(), QgsAttributeMap(), &context );
+      QCOMPARE( feature3.attribute( "T_Id" ).toInt(), 2 );
+      feature3.setAttribute( "url_behoerde", "url_behoerde" );
+      feature3.setAttribute( "url_kataster", "url_kataster" );
+      zustaendigkeitskataster->addFeature( feature3 );
+
+      QgsFeature feature4 = QgsVectorLayerUtils::createFeature( zustaendigkeitskataster, QgsGeometry(), QgsAttributeMap(), &context );
+      QCOMPARE( feature4.attribute( "T_Id" ).toInt(), 3 );
+      feature4.setAttribute( "url_behoerde", "url_behoerde_x" );
+      feature4.setAttribute( "url_kataster", "url_kataster_x" );
+      zustaendigkeitskataster->addFeature( feature4 );
+
+      zustaendigkeitskataster->commitChanges();
+
+      QCOMPARE( zustaendigkeitskataster->dataProvider()->featureCount(), 4l );
+    }
+
 };
 
 QGSTEST_MAIN( TestQgsExpression )

diff --git a/tests/src/providers/testqgsogrprovider.cpp b/tests/src/providers/testqgsogrprovider.cpp
@@ -130,6 +130,5 @@ void TestQgsOgrProvider::decodeUri()
   QCOMPARE( parts.value( QStringLiteral( "layerName" ) ).toString(), QString( "a_layer" ) );
 }
 
-
 QGSTEST_MAIN( TestQgsOgrProvider )
 #include "testqgsogrprovider.moc"
diff --git a/tests/testdata/kbs.gpkg b/tests/testdata/kbs.gpkg